Ara Ko

Resveratrol (RSV) is a natural polyphenol that has a beneficial effect on health, and resveratrol-induced autophagy has been suggested to be a key process in mediating many beneficial effects of resveratrol, such as reduction of inflammation and induction of cancer cell death. Although various resveratrol targets have been suggested, the molecule that mediates resveratrol-induced autophagy remains unknown. Here, we demonstrate that resveratrol induces autophagy by directly inhibiting the mTOR-UL

Dysregulation of O-GlcNAc modification catalyzed by O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA) contributes to the etiology of chronic diseases of aging, including cancer, cardiovascular disease, type 2 diabetes, and Alzheimer's disease. Here we found that natural aging in wild-type mice was marked by a decrease in OGA and OGT protein levels and an increase in O-GlcNAcylation in various tissues. Genetic disruption of OGA resulted in constitutively elevated O-GlcNAcylation in embryos and led

The mammalian target of rapamycin (mTOR) interacts with raptor to form the protein complex mTORC1 (mTOR complex 1), which plays a central role in the regulation of cell growth in response to environmental cues. Given that glucose is a primary fuel source and a biosynthetic precursor, how mTORC1 signaling is coordinated with glucose metabolism has been an important question. Here, we found that the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) binds Rheb and inhibits mTORC1 s

Muscle atrophy occurs under various catabolic conditions, including insulin deficiency, insulin resistance, or increased levels of glucocorticoids. This results from reduced levels of insulin receptor substrate 1 (IRS-1), leading to decreased phosphatidylinositol 3-kinase activity and thereby activation of FoxO transcription factors. However, the precise mechanism of reduced IRS-1 under a catabolic condition is unknown. Here, we report that C1-Ten is a novel protein tyrosine phosphatase (PTPase)

As a result of the increased demand for minimally invasive surgery, single-port laparoscopic surgery performed via a single incision was introduced and has been performed in various fields. Herein, we report our initial experience with single-port laparoscopic appendectomy (SP-LA) using Gelport access for the treatment of acute appendicitis in 2 pregnant women. SP-LA using Gelport access was performed successfully in these pregnant women without prolongation of operation time, and there was no n

Parkinson’s disease (PD) is characterized by the selective degeneration of midbrain dopaminergic neurons and aggregation of α-synuclein. Emerging evidence implicates the gut microbiome in PD, with microbial metabolites proposed as potential pathological mediators. However, the specific microbes and metabolites involved, and whether gut-derived metabolites can reach the brain to directly induce neurodegeneration, remain unclear. Here we show that elevated levels of Streptococcus mutans (S. mutans

In the evolving landscape of cancer research, the human microbiome emerges as a pivotal determinant reshaping our understanding of tumorigenesis and therapeutic responses. Advanced sequencing technologies have uncovered a vibrant microbial community not confined to the gut but thriving within tumor tissues. Comprising bacteria, viruses, and fungi, this diverse microbiota displays distinct signatures across various cancers, with most research primarily focusing on bacteria. The correlations betwe

The gut microbiome is widely recognized as a dynamic organ with a profound influence on human physiology and pathology. Extensive epidemiological and longitudinal cohort studies have provided compelling evidence that disruptions in the early-life microbiome can have long-lasting health implications. Various factors before, during, and after birth contribute to shaping the composition and function of the neonatal and infant microbiome. While these alterations can be partially restored over time,

Amitriptyline is a tricyclic antidepressant that is metabolized mainly by CYP2C19 and CYP2D6 enzymes. Higher plasma levels of amitriptyline and its active metabolite, nortriptyline, are associated with an increased risk of adverse events including anticholinergic effects. The aim of this study was to evaluate the effects of CYP2C19 and CYP2D6 genetic polymorphisms on amitriptyline and nortriptyline pharmacokinetics. Twenty-four Korean healthy adult male volunteers were enrolled in the study afte

Recent reports indicate that Parkinson's disease (PD)-like changes in gut microbial signatures develop in idiopathic REM sleep behavior disorder (iRBD), a prodrome of α-synucleinopathies. However, <50% of PD cases exhibit RBD at onset, underscoring PD's heterogeneity. Using untargeted metabolomics, plasma samples from PD patients with and without RBD, iRBD subjects, and healthy controls were analyzed to characterize the metabolic differences in PD patients with and without RBD. Metabolomic analy